Strong associations exist between cardiovascular events and increased carotid artery wall intima-media thickness (IMT) as measured non-invasively by carotid ultrasound. Carotid IMT is accepted as a surrogate marker of sub-clinical cardiovascular disease. We propose to determine the rate of progression of sub-clinical cardiovascular disease (change in IMT) over a period of 8 to 10 years. Imaging and IMT measurements of approximately 2800 to 3000 members of this cohort having had baseline IMT measurements at their 1995-98 clinic visit will be repeated in 200:5-2007. The principal aims of the project are to study the primary hypotheses that: 1. Interim exposure to traditional cardiovascular risk factors measured over 50 years is positively associated with the progression rate of carotid IMT. 2. Baseline carotid IMT and cumulative exposure to cardiovascular risk factors 20 years before the baseline visit are a better predictor of progression of sub-clinical disease after 8 to 10 years than the interim exposure to risk factors. 3. Novel risk factors such as C-reactive protein and homocysteine affect progression of carotid atherosclerosis more than traditional risk factors. This application will add a phenotypic marker of site-specific change in sub-clinical cardiovascular disease to the Framingham Study database. This complements ongoing research on the progression of sub-clinical cardiovascular disease and its associations with family history of premature cardiovascular events and genomic markers.